1. Field of the Invention
The present invention relates generally to medical devices and methods, and in particular to a device and method for therapeutically treating edema and related swelling in a body trunk and/or extremity such as an arm, hand, foot or a leg, through compressive application of pillows containing buckwheat hulls.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Edema adversely effects numerous persons and animals each year. For some, it occurs chronically, as a result either of an acquired disease or of a hereditary condition. For others edema occurs as a temporary condition, consequent to lymphatic disorders or from post-operative inflammation or stress. Swelling from edema also causes disruption of the normal flow of bodily fluids, and may cause further damage to the body.
Edema presents the problem of the presence of abnormally large amounts of fluid in the intercellular tissue spaces of the body; most commonly referring to a demonstrable accumulation of excessive fluid in the subcutaneous tissues. Edema may be localized, due to venous or lymphatic obstruction or to increased vascular permeability, or it may be systemic due to heart failure or renal disease. One type of edema characterized by the accumulation of excess fluid in the subcutaneous tissues is lymphedema.
Lymphedema may exist as the primary or secondary type. The primary type can be present from birth (congenital lymphedema) or may occur during puberty (lymphedema praecox) or less frequently later in life (lympdema tarda). Primary lymphedema occurs less often in men. The patient complains of swelling of the foot, leg, or an entire extremity. Usually unilateral, it is worse during warm weather and before menstrual periods. There are usually no visual skin changes or evidence of venous insufficiency.
Secondary lymphedema is often a result of infection, especially dermatophytosis when it occurs in the foot. The onset is explosive, with chills, high fever, toxicity, and a red, hot swollen leg. Lymphangitic streaks may be seen in the skin, and lymph nodes in the groin are usually enlarged and tender. These features distinguish it from acute thrombophlebitis. Secondary lymphedema in older persons may be due to malignant disease in the pelvis or groin. Obliteration of lymphatic tissue by excision or radiation therapy is another cause.
Secondary lymphedema frequently attends surgical procedures which are being performed with increasing frequency. Mastectomy, especially radical mastectomy and even lumpectomy involves the intentional removal of lymph nodes in the axillary region. Such removal may have a systemic effect because the injury occurs near the entrance of the lymphatic ducts to the subclavian veins. Prostatectomy, orchiectomy, bladder surgery and hysterectomy all involve significant dissection of the lymphatic system in the pelvic and abdominal areas.
The lymphatic system in the extremities parallels the venous system. In the legs, beginning in the dorsal region of the foot, the lymphatic ducts curve around the internal malleolus and ascend along the inner margin of the limb. In the arm, the system is analogous, beginning on the dorsal region of the hand and ascending to the axillary region. Trauma to any extremity, especially compound fractures, inevitably damages the lymphatic system. Finally, non-invasive diagnostic and therapeutic procedures such as radiation therapy in oncology can destroy lymph nodes or ducts in the treatment region.
Lymphedema is not only a primary concern because of the resultant swelling, heaviness and weakness causes discomfort. The diminished function of the lymphatic system predisposes the patient to opportunistic infections and further injury of a mechanical nature.
Excellent survey articles directed to the understanding and care of lymphedema include S. R. J. Thiadens, “Lymphedema, An Information Booklet”, National Lymphedema Network, San Francisco, 1996, C. A. Humble, “Lymphedema”, Oncology Nursing Forum, 22, 1503 (1995) and C. Wilson, ed., J. Cardiovas. Nur., 4, 79 (1989). Treatment which is non-invasive and suffices in most cases involves massage, preferably with an external compressive device (ECD) formed from a series of chambers which inflate serially to serve as a type of peristaltic pump. Subsequently, a more portable compress may be used during “working hours.” Conventional compresses are formed from some type of elastic material and, for the treatment of lymphedema and other circulatory diseases, may include shaped rubber pads. Devices of this type are heavy, breathe poorly and are generally uncomfortable in the summer. Allergic response may be a concern as many people are or become sensitized to synthetic and natural rubbers, especially latex.
An example of constant pressure devices include Schneider packs, used to compressively apply small packs of randomly placed pieces of high density foam bound within a tubular cloth pouch or tube.
U.S. Pat. No. 5,976,099 discloses compressing a plurality of particles in a multiplicity of pockets arranged in a chevron configuration against a swollen body area to thereby create a network of relatively narrow low pressure channels within a relatively large high pressure surface area. The device comprises an enclosure of compressible, high resiliency, low density, open cell plastic foam such as polyurethane particles and a compressive means with which to apply the enclosure. Though this reference suggests the simultaneous use of particles having various shapes, resiliency and density, it does not suggest the use of hollow, collapsing and expanding, hard shell particles. Nor does this reference suggest using biodegradable and naturally available particles which inherently maintain a sustained and indefinite cooling effect due to superior heat transfer properties.
U.S. Pat. No. 5,916,183 discloses a sheet of convoluted plastic foam and a means to push the extending elements, or fingers, of the convoluted foam sheet against a swollen body part. The use of solid convoluted sheets adds undue weight and restricts movement. Such device typically weighs three pounds.
U.S. Pat. No. 5,697,962 discloses a therapeutic wrap which is disposed on opposite sides of the knee and receives hot or cold substances without being removed from the knee. Even so, frequent replacement is required, which may cause pain or aggravate an associated injury.
U.S. Pat. No. 4,064,578 discloses a two layer slidable seat cushion having a fibrous layer containing buckwheat. A sponge mat layer exists between the fibrous layer and the patient. Buckwheat is used as a fibrous material to allow layer shifting. The use of granular material enables the lower portion of the patient's body to move smoothly in the forward direction without any pressure being applied to the body. Thus, this reference teaches away from the compressive therapy of the present invention.
U.S. Pat. No. 5,363,524 discloses a pillow having upper and lower fabric panels and a flowable filler material such as buckwheat hulls therebetween. This pillow provides support for the neck and other portions of the body.
U.S. Pat. No. 5,758,375 discloses a body support and bed pillow containing a granular material such as buckwheat. This pillow provides support for the neck and other portions of the body whereby users can redistribute filling material in a predetermined configuration by tightening a drawstring.
U.S. Pat. No. 5,809,594 discloses a combination pillow containing buckwheat husk which supports the cervical vertebrae and an occipital region of the user. The disclosed pillow is intended also to assist in preventing the user's head from coming off of the pillow.
U.S. Pat. No. 5,363,524 discloses a buckwheat pillow. No mention is made that such a pillow would be beneficial for the treatment of edema. More importantly, this pillow is not adapted for use in compressive therapy or for effective heat transfer.
There remains a need for a comfortable compressive device for the treatment of lymphedema which is both effective and comfortable.